Scaling down of complementary metal-oxide semiconductor (CMOS) transistors results in increased power consumption and short channel effects. Tunnel field-effect transistors (TFETs), which use a band-to-band tunneling (BTBT) mechanism, have been investigated as one of the more promising next-generation devices for low-power applications. TFETs are devices suited for low power applications because the TFETs, for example, exhibit steep subthreshold swing and weak temperature dependence.
TFETs also exhibit relatively low on-current (Ion), which can be undesirable. A heterostructure (source-channel) has been used to boost the on-current in a TFET. However, there remains a need for improved semiconductor device structures and methods of forming the same which address the need for increasing on-current.